As is known, tyre research is partly focused on achieving treads with improved performance in terms of rolling and wear resistance.
For this purpose, silica has long been used as a reinforcing filler in tread compounds, as a substitute for carbon black, because of the advantages it affords in terms of rolling resistance and wet road-holding performance.
Silica is used in conjunction with silane bonding agents, which, bonding with silanol groups, prevent the formation of hydrogen bonds between silica particles and, at the same time, bond the silica chemically to the polymer base.
Trialkoxymercaptoalkyl-silanes are a particularly interesting class of silane bonding agents because of the advantages they afford in reducing both rolling resistance and the emission of volatile substances.
The compound which has proved most effective is:SH(CH2)3Si(OCH2CH3)(O(CH2CH2O)5(CH2)13CH3)2 
This class of silane bonding agents, however, has been found to pose problems in terms of processing. More specifically, the presence in a rubber compound of a trialkoxymercaptoalkyl-silane compound may increase the viscosity of the rubber compound, with obvious effects on its ability to be processed.
To solve the processing problems involved, plasticizing oils are normally added to the rubber compound, but, alongside a reduction in viscosity, also impair the rubber compound in terms of wear resistance. The common practice is to reduce the effect on wear resistance by increasing interaction between the silica, silane bonding agent and polymer at the curing stage, but this has the effect of reducing scorch time.
A need is therefore felt for a method designed to solve the processing problems posed by using trialkoxymercaptoalkyl-silanes, but without incurring other drawbacks in terms of wear resistance or reducing scorch time.